Quantum coherence tomography of light-controlled superconductivity
Quantum coherence tomography of light-controlled superconductivity
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DOI：
10.1038/s41567-022-01827-1
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发表时间：
2022-12-05
期刊：
影响因子：
19.6
通讯作者：
Wang, J.
中科院分区：
文献类型：
--
作者：
Luo, L.;Mootz, M.;Wang, J.
超导体与光脉冲振荡周期之间的耦合，即，光波工程是超导量子电子学的新兴控制概念。虽然在太赫兹驱动的超导性和超电流方面取得了进展，但能够驱动非平衡配对的相互作用仍然知之甚少，部分原因是缺乏高阶相关函数的测量。特别是，以类似于迈斯纳效应的方式感测独特的光驱动超导相干性的奇异集体模式是非常具有挑战性但非常需要的。在这里，我们报告的发现参数驱动的超导电性的光诱导有序参数集体振荡的铁基超导体。耦合的电子和空穴带之间的时间周期性的相对相位动力学驱动的过渡到一个独特的参数超导态的不平衡。这种光诱导的出射相干性的特征在于独特的相位-振幅集体模式，其具有两倍于希格斯频率的Floquet样边带。我们测量非微扰，高阶相关性的参数驱动的超导分离太赫兹频率的多维相干谱成泵探测，希格斯模式和双希格斯频率边带峰。我们发现，高阶双希格斯边带占主导地位的临界场以上，这表明在这个参数量子物质的磁化率微扰膨胀的崩溃。
The coupling between superconductors and oscillation cycles of light pulses, i.e., lightwave engineering, is an emerging control concept for superconducting quantum electronics. Although progress has been made towards terahertz-driven superconductivity and supercurrents, the interactions able to drive non-equilibrium pairing are still poorly understood, partially due to the lack of measurements of high-order correlation functions. In particular, the sensing of exotic collective modes that would uniquely characterize light-driven superconducting coherence, in a way analogous to the Meissner effect, is very challenging but much needed. Here we report the discovery of parametrically driven superconductivity by light-induced order-parameter collective oscillations in iron-based superconductors. The time-periodic relative phase dynamics between the coupled electron and hole bands drives the transition to a distinct parametric superconducting state out-of-equalibrium. This light-induced emergent coherence is characterized by a unique phase-amplitude collective mode with Floquet-like sidebands at twice the Higgs frequency. We measure non-perturbative, high-order correlations of this parametrically driven superconductivity by separating the terahertz-frequency multidimensional coherent spectra into pump-probe, Higgs mode and bi-Higgs frequency sideband peaks. We find that the higher-order bi-Higgs sidebands dominate above the critical field, which indicates the breakdown of susceptibility perturbative expansion in this parametric quantum matter.